A variety of systems are known for packaging foodstuffs in closed containers and a few of the known systems will now be described.
For packaging solid foodstuffs, for example cakes, it is known to use lidded boxes formed from cardboard blanks, the lids either being made integral with or separate from the box, by being folded from the box blanks or being folded from lid blanks separate from the box blanks. It is alternatively known to mould paperboard, plastics, or metal foil, to form solid-foodstuff-receiving trays which may have one or more receiving compartments, and then to wrap the foodstuffs and the trays in plastics or metal foil.
For packaging liquid foodstuffs, where fluid-tightness is important, it is known to fit paperboard or plastics lids in a fluid-tight manner on cups of plastics or paperboard, the paperboard having at least at its inside a liquid-tight layer, for example a thermoplastics relatively impervious to the liquid foodstuff. It is known alternatively to fold a paperboard blank coated on at least one side with a liquid-impervious layer into the form of a side-and-bottom-sealed open-topped carton, with that one side, at the inside of the carton, and then to fill and top-seal the carton.
EP-A-0274280 discloses a system of packaging of foodstuffs in containers of rectangular horizontal section. The containers are formed by folding and side-and bottom-sealing blanks of paperboard coated on both sides with thermoplastics. Each open-topped container is sterilized, filled, and closed with a sterilized closure. The closure is of a laminate including a thermoplastics layer of sufficient thickness to fill an internal discontinuity of the container mouth during heat-sealing of the closure to the container. In making the closure, a portion of laminate is partially severed to form a flap and the laminate is clamped around the flap and drawn to form a shallow dish, to the inside of the base of which is heat-sealed a diaphragm including a pull tab. The thermoplastics layer of the closure is on a reflective metal layer and incorporates infrared-absorbing particles and infrared-reflective particles. Among the drawn zones are transverse rectangular slots which facilitate drawing of the laminate material without splitting, in spite of the sharp corners of the rectangular shape of each drawn zone. However, the presence of the slots can result in undesired deformation of the material among the slots on drawing, because of insufficient support for the material bounding the slots.
GB-A-998242 discloses an apparatus for turning match books which are being transferred one after another from a book-match-making machine to a packing station. A guideway connects the output of the machine to a turning chamber and an endless chain advances the match books in line along the guideway to a guide which maintains the match books upright in a vertical position. Above the guide is a microswitch the movable contact of which depends into an opening in the guide. After the match books have been advanced to a position under the guide, they are clamped, one-by-one, by a feeding slide which rapidly advances them past the microswitch, thereby to operate the same, to the turning chamber, in which they are turned into horizontal positions by means of jets of compressed air, after which they are ejected by a plunger into an arcuate chute forming a downwards continuation of the turning chamber. The compressed air jets are provided by four pairs of nozzles, two pairs arranged one above the other at one side of the turning chamber and the other two pairs arranged one above the other at the opposite side of the turning chamber, the four nozzles at the one side being directly opposite the respective four nozzles at the opposite side. Since the match books have a profile which is wedge-shaped, every second match book is turned in a sense opposite to that in which the other match books are turned, thereby ensuring that the match books stack horizontally in a vertical stack. Such turning is achieved by so timing the jets from the nozzles that simultaneous jets from the upper pair of nozzles at the one side and the lower pair at the opposite side, to turn one match book about a central horizontal axis thereof clockwise, say, to a horizontal position are followed by simultaneous jets from the lower pair of nozzles at the one side and the upper pair at the opposite side, to turn the next match book about a central horizontal axis thereof anti-clockwise, say, to a horizontal position. This apparatus is relatively complicated and requires very accurate timing of release of the match books by the feeding slide and production of the Jets from the nozzles.
GB-A-1112243 discloses an apparatus for grouping bags, containing stockings for example, inside an open-topped rectangular container. A belt conveyor drops the bags into a chute obliquely inclined at its upper end but curving downwards to its substantially vertical lower end, whence the bags, while vertical, drop vertically into the container, which is horizontal. The bags are held vertically in position in the container by a vertical plate which is carried by a rod suspended from a roller running on a sloping rail and which is retractable from a filled container. The bags are dropped into each container adjacent one end wall, which is formed with holes through which horizontal pusher pins are introduced to push each dropped bag in turn along the container to join the row of already dropped bags therein. As the bag is pushed along to join the row, its upper edge is forced to pass under a nose of a curved guide sheet and its lower edge is forced to pass over a boss at the beginning of transverse corrugations formed on the bottom of the container. Once a container is filled, it is advanced horizontally away by a chain conveyor and an empty container is brought into position beneath the chute. This apparatus includes relatively complicated mechanisms for advancing the dropped bags along the horizontal container and maintaining them vertical therein.
U.S. Pat. No. 2,356,021 discloses an apparatus for oscillating a rectangular receptacle, containing small, light-weight articles, such as container caps or closures, about a horizontal axis below the middle of the receptacle. Two receptacles are mounted side-by-side upon respective rectangular frames tiltable about that axis by respective vertical, shaking, piston-and-cylinder devices, in order to settle the articles in the receptacles.
U.S. Pat. No. 3,270,903 discloses a system for handling empty lightweight plastics bottles and particularly for removing such bottles from shipping or storage containers. A belt conveyor advances the containers in turn onto a platform which is apertured at its front section and mounted upon a horizontal pivot at its rear section. At the front of the platform is an eccentric formed so as to oscillate the platform longitudinally of the pivot and about the pivot, simultaneously, in order to vibrate the entire platform sufficiently to jar loose any bottles which might tend to stick in the carton and thus to ensure that they fall through the apertures at the front section into chutes, whence they are conveyed to a filling machine.
GB-A-654617 discloses a conveyor for cartons, in which the cartons are advanced by being gripped between two flat endless belts moving around vertical rollers.
U.S. Pat. No. 4,313,476 discloses a filling machine for filling containers with a quick-drying fluid product by the use of a bank of filling nozzles. The machine includes two substantially parallel filling channels which are formed in part by two separate conveyors, a vacuum filling mechanism connected with the filling nozzles, a support for the filling nozzles, a mechanism for lowering and raising the nozzle support and therewith the filling nozzles into and out of containers held stationary under the filling nozzles, an indexing mechanism for determining the correct number of containers to be filled at the same time in a respective channel during a given filling operation while the associated conveyor is stationary and the containers being filled are held stationary in their filling positions, a reciprocating mechanism for the nozzle support alternately to place the filling nozzles over the containers to be filled in one channel and after completion of the filling operation to move the nozzle support over the other channel to fill the containers which have been brought into filling position in the meantime in the other channel, and a control system for operating the filling machine. This machine requires a large number, for example a dozen, containers to be filled simultaneously, otherwise it becomes very inefficient owing to the time taken to traverse the bank of nozzles to-and-fro between the two channels.
GB-A-1062431 discloses a machine for use in packaging articles, such as leaflets, in cartons, comprising an endless conveyer the flights of which are spaced apart to receive cartons between them and are arranged to advance the cartons along stationary carton support, wherein the conveyer flights are distributed on two different parallel bands of the conveyer in arrangement such that the flights on one band define the leading extremities of conveyer carton-pockets while those on the other band define the trailing extremities of the pockets, wherein the two conveyer bands are relatively adjustable longitudinally to vary the conveyer flight spacings, and wherein the conveyer is elevationally adjustable with respect to the carton support. The machine receives the careens, in a collapsed flat-folded condition, in a magazine having a bottom guide surface downwardly inclined, at a decreasing gradient, to a restricted opening through which the collapsed cartons are pulled, one-by-one, by a suction cup arrangement, relying upon the flexibility of the cartons. A similar magazine and suction-cup arrangement, but for use with container lids, is disclosed in U.S. Pat. No. 4,122,649.
U.S. Pat. No. 1,476,737 discloses a package-conveying system including a conveying belt and a package feeler which, when the number of packages on the belt is normal, intermittently swings freely between the packages but, when there is an excess number of packages on the belt, is obstructed by a package and immediately sets into operation a normally inactive package pusher disposed upstream thereof and effective when actuated to remove successively the packages from the belt until such time as the number of packages on the belt has been restored to normal, whereupon the pusher is automatically thrown out of operation, and the feeler resumes its normal action.
U.S. Pat. No. 3,249,206 discloses an egg-handling machine including a chain conveyor for egg containers. The chain conveyor includes two parallel endless chains running on sprockets with horizontal axes of rotation. Extending transversely between the two chains are a plurality of horizontal pivot rods upon which are mounted a plurality of impellers having vertical leading walls and serving to impel the egg containers. Alternating with the impellets are carton-retaining members also mounted between the two chains upon horizontal pivot rods. When the impellets are in use for impelling containers in the form of cardboard grids, the carton-retaining members occupy lowered positions beneath the level of the grids. However, when two-row cartons are to be impelled, a camming ledge extending along the chain conveyor is swung from a lowered position into a raised position and thereby comes to bear upon and move upwards rollers depending from the carton-retaining members, thus to move the carton-retaining members into raised positions in which their trailing walls are substantially vertical. The distance between the vertical surface of each impeller and the substantially vertical surface of the raised carton-retaining member ahead of that impeller is arranged to be of a proper size snugly to receive and retain a two-row carton.
Various container-conveying apparatus are known, for example from U.S. Pat. No. 3,009,300, which include linear and/or rotary sliding couplings and/or bearings in their drive and/or control linkages. Especially when such container-conveying apparatus are used in foodstuff-packaging machines, a clean-in-place method is advantageously applied to such apparatus, but such method can leave on machine surfaces extremely hard crystalline deposits from the cleaning chemicals evaporating from those surfaces. Thus, wherever the mutually sliding surfaces are exposed, the exposed portions are particularly vulnerable to wear.
U.S. Pat. No. 2,719,663 discloses a container with a rip-open flap. The container is formed of cardboard or paper and comprises a tubular body having upstanding side walls and top and bottom closures. The top closure includes a top frame with an upper surface recessed below the upper edges of the side walls and surrounded by upstanding flanges. The top closure has an opening therein and a closure flap fitting in the opening. The top closure also includes a sealing flap completely covering the upper surface and the closure flap and fitting against the flanges, the sealing flap being covered substantially throughout its underside with adhesive to be secured permanently to the closure flap and releasably to the upper surface, the sealing flap having at its front an area free of but completely surrounded by adhesive. This area includes and overlaps the front end of the closure flap. The sealing flap has an extension at its front for fitting against the adjacent upstanding flange with the ends of the extension nesting in the corners of the flanges, and a tab on the extension for fitting over the front flange to facilitate opening the sealing flap. The closure flap is made of a stronger material than the appertaining container wall, so that the closure flap, in conjunction with the sealing flap, and with the layer of adhesive between them, form a relatively rigid and firm lid that keeps its even form and positively pivots about the rear edge of the closure flap in the tearing-open operation. There is, nevertheless, a risk that the sealing flap will tear within itself in such manner that the flap is torn short.
GB-A-1535653 discloses a cuboidal liquid-packaging container made of a laminated material which comprises a base layer of paper provided on each side with a layer of plastics. For opening the container a tear-open pull-tab is provided located mainly in the top surface of the container, but extending also partially over an edge into a side surface. The pull-tab which constitutes an integral part of the material of the container is defined by a weakening or perforation line which extends through all the laminate layers. The line is substantially U-shaped, with the legs of the U on the top surface of the package, whilst the part of the line which forms the base of the U runs over the edge and onto the side surface of the container. The U is wider at its base than at its free ends. To prevent the contents in the container from leaking out through the perforations of the weakening line, a cover layer is provided underneath the tear-open pull-tab and preferably consists of a strip of suitable plastics film bonded to the inside of the laminated material in a continuous sealing zone between the edge of the cover layer and the weakening line. Since the cover layer as well as the endless seal should be impervious to fluids, the contents of the container should not leach or leak out from the perforations of the weakening line, and, conversely, penetration of air into the package through the perforations should be substantially prevented. A flexible strip of plastics may be provided between the cover layer and the laminate, located within the area defined by the sealing zone. The main pan of the flexible strip is situated underneath, and extends parallel to the edges of, the tear-open pull-tab, while a front end of the strip extends a little beyond the edge of the container. To provide an outlet for pouring out the contents of the package after breaking the weakening line and lifting the tear-open pull-tab, the strip is provided with a substantially oval opening located at a little distance inside the container edge. To allow the container to be opened in one single action, the cover layer is sealed to the underside of the tear-open pull-tab over a second sealing zone extending round the periphery of the opening, and inside the line defining the opening.
Again, there is a risk that the tear-open pull tab is torn short.
In conventional manufacture of components for beverage and other food cans, shells are formed on a primary conversion press and are then collated into stacks before being fed into a secondary conversion press where a rivet dome and button are formed prior to attachment of a preformed pull-tab. The tab manufacture and the riveting both take place in the secondary conversion press. There are two disadvantages, one being that there is double handling of the component, which can lead to damage to components of non-rigid materials,.and another that, in certain cases, location of the rivet point cannot be accurately determined.